In certain medical procedures including interventional procedures such as angioplasty, angiography, and stenting, it often is necessary that an artery be punctured to gain access to the site needed to be diagnosed or treated, typically the region of the heart. The process of inserting the catheter in a proper position within the arterial lumen typically requires that many steps be performed involving inserting and removing various devices into the artery. At the end of the process, the devices are removed leaving a hole in the arterial wall that must be sealed, preferably as soon as possible. Failure to achieve hemostasis at the puncture site may lead to serious bleeding consequences, especially if the patient has been treated with anticoagulants, which often is the case with patients subjected to these procedures.
The artery most often used for this purpose is the femoral artery as it is relatively large and easy to locate. The femoral artery is punctured and a catheter is inserted into the lumen thereof to gain access to the site of concern. Access to the femoral artery is typically gained at the groin area. The femoral artery is easily located here, and the arterial wall is punctured with a needle. In a typical Seldinger technique, a guide wire is inserted through the needle into the lumen of the artery (the needle is hollow for this purpose). Once the guide wire is in place, the needle is removed. A procedural sheath or "introducer," and often a dilator within the introducer, are then both passed over the guide wire and inserted into the arterial lumen. The instrument used at this step of the process is referred to herein as the "introducer," as it is used to introduce procedural catheters, guiding catheters or other medical devices in the arterial lumen. The term "procedural sheath" is also used in the field to refer to the introducer device, and these terms are considered herein to be interchangeable. Once the introducer is in place, the guide wire and dilator may be removed. The catheter is fed through the introducer into the arterial lumen. As a result of these procedures, the practitioner can be assured that the catheter is properly positioned in the lumen of the artery.
This process is now explained more specifically with reference to FIG. 1. In FIG. 1, there is illustrated a typical introducer 10 which is shown lodged within the arterial lumen 12. The introducer 10 has a distal end or tip 101 inserted into the lumen, and a proximal end 102 protruding in the ambient beyond the surface 19 of the patient's skin. As can be seen, the distal end of the introducer adjacent the tip 101 is flexible so that it may bend within the lumen. In FIG. 1, a needle is used to puncture the skin surface 19, layers of fat tissue 16, and the arterial wall 18 forming a wound tract 20a through the patient's tissues and a puncture site 20 on the arterial wall. The process of inserting the introducer 10 through the puncture site 20 is performed as described above using a guide wire and dilator (not shown in FIG. 1). In FIG. 1, the catheter 30 has been inserted through the introducer with its distal end 30a protruding into the lumen beyond the tip 101 of the introducer and its proximal end 30b protruding into the ambient beyond the proximal end 102 of the introducer. As may be seen, the introducer thus enables the practitioner to properly position within the arterial lumen guiding catheters, procedural catheters, and other medical devices to effect treatment of the patient.
However, when the procedure is completed, the catheter and introducer need to be removed and the puncture site closed. Conventional treatment has been to remove these devices and then apply pressure, e.g., "manual compression," to the artery for a period of about twenty minutes to one-half hour or longer to induce hemostasis. This procedure typically requires a clamp or sand-bags and the attention of health-care professionals. Also, the patient is required to remain immobilized in a horizontal position for many hours, sometimes up to 24 hours, with sand-bags placed on the area of the puncture, i.e., the groin area. This is painful and uncomfortable for the patient and is inefficient in consuming resources of the health-care facility. Additionally, the wounds thus sealed often are prone to reopen, and this contingency requires additional monitoring by the health-care professionals and causes anxiety to the patient.
Recently, many efforts have been directed toward developing devices that may be used to better close the puncture site. For example, devices developed to accomplish this objective are disclosed in the following patents which are incorporated herein by reference: U.S. Pat. No. 5,741,223 issued Apr. 21, 1998 to Janzen et al., "Device and Method for Sealing Puncture Wounds" ("Janzen"); U.S. Pat. No. 5,354,271 issued Oct. 11, 1994 to Voda, "Vascular Sheath" ("Voda"); U.S. Pat. No. 5,441,517 issued Aug. 15, 1995 to Kensey et al., "Hemostatic Puncture Closure System and Method of Use" ("Kensey"); U.S. Pat. No. 5,324,306 issued Jun. 28, 1994 to Makower et al., "Hemostatic Implant Introducer" ("Makower"); U.S. Pat. No. 5,868,778 issued Feb. 9, 1999 to Gershony et al., "Vascular SealingApparatus and Method," and U.S. Pat. No. 5,792,152 issued Aug. 11, 1998 to Klein et al., "Device and Method for Suturing of Internal Puncture Sites." Objectives with these devices include reducing the morbidity of the procedure, enabling the patient to leave the hospital sooner, increasing the number of patients that can be treated daily, and reducing the amount of pain, discomfort, and distress endured by the patients. These devices employ sutures to close the artery or a variety of other means to deliver thrombogenic materials such as collagen to the outside of the artery. With these devices, a special additional applicator is typically used, either with or without the introducer, to deliver the thrombogenic materials to the puncture site.
For example, Janzen describes an apparatus for insertion of collagen to the puncture site. The Janzen device includes a dedicated sheath (e.g., an additional sheath besides the introducer), a collagen cartridge, and a collagen pusher. With this device, the introducer (10, FIG. 1) (referred to in Janzen as the "guide cannula"), is first removed with the guide wire left in place in the arterial lumen. The dedicated applicator of Janzen is then passed over the guide wire to the puncture site. With the Janzen device, the introducer is removed before closure is effected presenting the risk of bleeding at the puncture site. To avoid the risk that collagen will enter the arterial lumen, Janzen recommends that the end of the collagen applicator be larger than the arterial puncture. Also, Janzen requires an additional measuring step with use of a clamp and/or a kit of sheaths of varying lengths to measure arterial depth and locate the arterial puncture site (e.g., Janzen, col. 8, lines 38-55).
Voda shows a device referred to therein as a "carrier means" having suture threads located on its end (e.g., FIGS. 8-11 of Voda). The device of Voda provides advantages as compared with that of Janzen as closure of the puncture site is attempted without removal of the introducer, thus reducing risks associated with immediate bleeding at the puncture site. However, Voda requires an additional "carrier means" device. The carrier means is inserted into the introducer, and suture threads are then used to pull the puncture site closed. Closure of the puncture site with suture threads in this way may present considerable challenges to the practitioner. The Klein and Andreas patents likewise disclose devices for suturing the puncture site.
Kensey shows a device for delivery of collagen to the puncture site and puncture tract. Again, in Kensey, a special applicator is used. There, the applicator is inserted into a dedicated procedural sheath (other than the introducer used to position the catheter). An anchor member is placed on the tip of the applicator, and a collagen plug is secured within the applicator adjacent the tip. A filament traverses the length of the applicator and also connects the anchor member and the plug. The Kensey device provides advantages in that one sheath length fits all arterial depths, and a configuration is provided (e.g., the anchor member) to seek to position the collagen plug at the puncture site. However, in Kensey the anchor member remains in the arterial lumen after closure of the puncture is completed. Thus, a foreign object potentially impedes the natural flow of blood to the peripheral vasculature and could become dislodged. Also, as may be appreciated, the applicator with its spring-loaded arrangement is relatively complicated.
Other devices that use collagen plugs to effect closure of the puncture site are shown in U.S. Pat. No. 5,192,300, issued Mar. 9, 1993 to Fowler, "Insertion Assembly and Method of Inserting a Vessel Plug Into the Body of a Patient," and U.S. Pat. No. 5,522,840, issued Jun. 4, 1996 to Krajicek, "Device for the Non-Surgical Seal of the Interstice in the Wall of a Vessel," which are incorporated herein. The Fowler device requires use of a separate balloon catheter to locate the puncture site as well as a collagen applicator. The balloon catheter is inserted through the introducer catheter, the introducer catheter is removed, and then the collagen plug is inserted to the puncture site along the shaft of the balloon catheter. The balloon catheter is then removed such that the only means of retaining the plug at the puncture site is tissue at the puncture site surrounding the plug.
Gershony also utilized an inflated balloon to locate the puncture site, but it is a separate device (not a balloon catheter). Gershony relied on a subsequent injection of procoagulant substances through the introducer sheath, presenting the risk of pushing the liquid-like substances into the vasculature and producing an embolism. The Krajicek device comprises a particular type of collagen plug and an applicator that may be applied to the exterior of the introducer. The Krajicek device does not include a mechanism for locating the puncture site. Makower shows a device similar to Krajicek in that thrombogenic materials are disposed concentrically surrounding the introducer which are pushed down the length of the introducer to the puncture site. Like Janzen, Makower requires a measuring procedure before the start of the closure procedure, e.g., a sheath and dilator having graduated markings are used (col. 6, 1. 18-20).
As can be seen, many of these devices require use of additional, specialized applicators. These applicators present disadvantages in that, among other things, they impose further costs on the procedure and may lead to additional bleeding while the special applicator is positioned for deployment. These applicators, being separate devices, are expensive. An additional step must be performed, requiring more time and training of the health-care professionals, and in some cases the catheter and introducer must be removed, presenting the risk of bleeding. Also, some of the devices lack a means for locating the arterial puncture site. Where mechanisms are not provided for precisely locating the puncture site, there is a risk that thrombogenic materials will enter the lumen.
As may be appreciated, those involved in the field of medical devices, and particularly medical devices useful for vascular sealing, continue to seek to develop new designs to quickly seal puncture sites. In particular, it would be advantageous to have a device that can quickly and easily deliver thrombogenic materials to the puncture site exterior the artery. It also would be advantageous to provide a mechanism for delivering these materials to the puncture site without having to remove the original procedural introducer and without having to incur the expense and technical difficulties associated with additional applicator devices.